Everyone is correct in stating that you should start by speaking with a mortgage consultant. During this conversation expect to have the mortgage process explained to you in detail and have all of your questions answered.
As part of the pre-approval process be prepared to answer questions regarding your employment, income, assets and credit history. With this information your mortgage consultant will be able to provide you with a full detailing of the financing options available to you, point out to any attributes specific to your situation that may be a hurdle in obtaining financing and discuss ways to overcome these issues, if any.
The way I work, I like to have an initial 10-20 minute conversation where I answer a new client's general finance questions, gather their information and discuss their desires specific to the property they are interested in purchasing.
After this conversation, I then do my research and analysis to put together a document with a detailed breakdown of various mortgage options that meet the client's specific desires and constraints. In this document I list all costs associated with owning the home and derive what I call the "net after-tax housing expense". I provide this information in a table format which allows the client to compare all options side by side. I also create and send to the client a short video where I review and discuss each option. I find that this particularly assists first-time home buyers and allows them to better understand what may be complex information.
Each mortgage consultant works differently, so make sure you work with someone that you feel comfortable with.